Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4eea20ae199cb72d…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:47:11 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: b28168e1a476f15fbe619457c0939505 SHA-1: f22ead4202030669d6479df188293e0bee8f4c6d SHA-256: 4eea20ae199cb72d41c9f040123fc12ff900fd1f0c8768d8188fab3b2c223e8b
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The critical heuristics indicate the presence of Excel 4.0 macros with dangerous formula APIs, specifically an Auto_Open function. This strongly suggests the macro is designed to execute arbitrary code upon opening the document. The macro sheet itself contains a large amount of obfuscated data, further supporting the likelihood of a malicious payload being embedded or downloaded.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6551 bytes
SHA-256: a9e54e6eefeec02228cf77c3ed31f3242b1d69f3e47d9df7d3ab83d3295950e1
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  fDGxhQQW
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!I164 
' 0018     24 LABEL : Cell Value, String Constant - cQeSEKWZX len=0 
' 0018     27 LABEL : Cell Value, String Constant - FdRuymBydzSE len=0 
' 0018     22 LABEL : Cell Value, String Constant - FPrrBRK len=0 
' 0018     23 LABEL : Cell Value, String Constant - IkoYLLoJ len=0 
' 0018     27 LABEL : Cell Value, String Constant - jFDXJIqGMWvq len=0 
' 0018     20 LABEL : Cell Value, String Constant - JJbtV len=0 
' 0018     23 LABEL : Cell Value, String Constant - jlgUymtM len=0 
' 0018     26 LABEL : Cell Value, String Constant - kKhJwBTbisb len=0 
' 0018     23 LABEL : Cell Value, String Constant - LnwCYZqn len=0 
' 0018     26 LABEL : Cell Value, String Constant - NAZSppxfsbW len=0 
' 0018     22 LABEL : Cell Value, String Constant - nLjBHLZ len=0 
' 0018     20 LABEL : Cell Value, String Constant - PFnqW len=0 
' 0018     27 LABEL : Cell Value, String Constant - qCeAsrddHfqO len=0 
' 0018     20 LABEL : Cell Value, String Constant - RzSEo len=0 
' 0018     22 LABEL : Cell Value, String Constant - SELjpAF len=0 
' 0018     20 LABEL : Cell Value, String Constant - TbJcN len=0 
' 0018     24 LABEL : Cell Value, String Constant - TuZZKqfvX len=0 
' 0018     24 LABEL : Cell Value, String Constant - VgIekbbnQ len=0 
' 0018     25 LABEL : Cell Value, String Constant - XNmYLcQBso len=0 
' 0018     27 LABEL : Cell Value, String Constant - ZgRhAQlTDRbv len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd
... (truncated)

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